Računanje fononske disperzije u nekristalnim magnezijevim legurama

The computation of the phonon dispersion curves (PDC) and the related properties of three Mg-based metallic glasses, viz. Mg70Zn30, Mg84Ni16 and Mg85.5Cu14.5, are made using the well recognized model potential of Gajjar et al. The pseudo-alloy atom model is applied for the first time instead of the Vegard\u27s law. The three theoretical approaches given by Hubbard-Beeby, Takeno-Goda and Bhatia-Singh are used in the present study to compute the PDC of the systems. Five local-field correction functions proposed by Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. are employed for the first time to see the effects of exchange and correlation. The thermodynamic and elastic properties are computed from the elastic limits of the PDC and found to be in qualitative agreement with the available theoretical or experimental data. The present findings for the PDC of Mg70Zn30 alloy are found in fair agreement with available theoretical and experimental data.Primjenom poznatog potencijala Gajjar-a i sur., izračunali smo fononske disperzijske funkcije (FDF) i fizička svojstva triju metalnih stakala na bazi magnezija, Mg70Zn30, Mg84Ni16 i Mg85.5Cu14.5. Prvi puta primjenjuje se model pseudo-leguraatom umjesto Vegardovog modela. Primijenili smo tri teorijska pristupa, HubbardBeeby-ev, Takeno-Goda-ov i Bhatia-Singh-ov za izračunavanje FDF. Radi nalaženja učinaka izmjene i korelacija, prvi smo uveli pet funkcija za popravke lokalnog polja, prema autorima Hartree-u, Taylor-u, Ichimaru-Utsumi-u, Farid-a i sur. te Sarkar-a i sur. radi nalaženja učinaka izmjene i korelacija. Izračunali smo termodinamička i elastična svojstva na osnovi elastične granice FDF i nalazimo dobar sklad s objavljenim teorijskim i eksperimentalnim podacima. Ishodi za FDF legure Mg70Zn30 su u razumnom skladu s teorijskim i eksperimentalnim podacima